Mozilla Marionette to test in-product URLs from Firefox chrome

Pontifications

"Marionette is an automation driver for Mozilla's Gecko engine. It can remotely control either the UI or the internal JavaScript of a Gecko platform, such as Firefox. It can control both the chrome (i.e. menus and functions) or the content (the webpage loaded inside the browsing context), giving a high level of control and ability to replicate user actions. In addition to performing actions on the browser, Marionette can also read the properties and attributes of the DOM.

If this sounds similar to Selenium/WebDriver then you're correct! Marionette shares much of the same ethos and API as Selenium/WebDriver, with additional commands to interact with Gecko's chrome interface. Its goal is to replicate what Selenium does for web content: to enable the tester to have the ability to send commands to remotely control a user agent."